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-   -   Steve and Aaron's 51PP9200D-37 Project (https://www.hometheatershack.com/forums/philips-magnavox/43592-steve-aarons-51pp9200d-37-project.html)

SLR_65 02-22-11 09:57 PM

Steve and Aaron's 51PP9200D-37 Project

Hi Guys,

My son and I just picked one of these up. Why? I dunno :dontknow: , it's a sickness! And it was FREE! :bigsmile:

It has the convergence out, and it's a Philips so it'll probably need the CRT fluid changed (oh joy!).

Where it's home will be after it's repaired, I'm not sure . . . maybe it'll become a dedicated gaming set at my son's or something . . . Did I mention it was FREE? LOL! :rofl:

My son Aaron is going to be the lead worker on this set (I figured it was worth the price of parts just for a fun father/son project).

We just picked it up so I have given the once over yet, I'm just in the info gathering stage right now.

*) First things first - a service manual. I found one here, some of this page is in spanish, but enough is in English you can see what to download and the manual it's self is in English.

*) Convergence chips - This set uses 2 of the STK392-120 and it appears to me that that's the best choice? This chip is rated at 4 amps and the STK392-150 is rated at 3? From what I gathered by doing some net surfing, the STK394-160 isn't an option in these sets as it doesn't work? I saw a couple references to using STK392-180 chips in this set but I couldn't find a spec sheet on them and Acme, where I like to get my chips from, doesn't carry them anyway. Am I correct the 120 is the best choice, or is there a better one? (I don't have to use Acme, if a 180 or something else will be more reliable I have no problem going to Encompass, etc.)

*) Convergence resistors - looks like there's 12 6.8 ohm 1 watt 5% metal film flame proof resistors for R3149, R3150, R3151, R3152, R3153, R3154, R3155, R3156, R3157, R3158, R3159 and R3160.

That's as far as we've gotten, we'll post more as the project progresses . . . and we'd welcome any comments, tips, or suggestions!

Take care,

SLR_65 02-23-11 03:22 PM

Re: Steve and Aaron's 51PP9200D-37 Project

You're welcome Mechman!

Do you care to weigh in on the STK392-120 substitution topic?

I think there is no improved sub for the 120.

I dug up data sheets for the 110, 120, and 150. I couldn't find one for the 180, but I found a reason for that - it's a proprietary chip.

From what I gather:

STK392-110 3 Amp device, +/- 38V
STK392-120 4 Amp device, +/- 44V
STK392-150 3 Amp device, +/- 38V

STK392-180 was custom made for Pioneer to replace the 110. Evidentally Pioneer claimed that the 110 had been running excessively hot and Sanyo revised the 110 with heavier bonding wires as well as employing less lead and more silver in the bonding process. One should consider this a 3 amp part as it's the same die as the 110.

Hitachi says stk392-150 replaces stk392-110
Pioneer says stk392-180 replaces stk392-110
Hitachi says do not use -180 in their sets

The STK394-160 was also a custom chip and it was Hitachi's replacement for the 110, 120, and 150 so it's evidentally at least a 4 amp device but I've read lots of posts on the net where these chips didn't work in Philips products. Nothing specific to this set but the schematic of this set looks similar to other models that have been listed as having issues with this chip so I don't think it's worth the gamble.

All in all, it looks like we'll be ordering some STK392-120s!


lcaillo 02-23-11 07:29 PM

Re: Steve and Aaron's 51PP9200D-37 Project

We were never able to get datasheets for the STK392-180 nor the STK394-160 so we do not know precisely. It has generally been assumed by those who have researched it most that the 394-160 and the 392-180 are 3 amp max chips. There is no sub for the 392-120.

The STK392-110 was a problem part for many manufacturers for a couple of reasons. It was marginal to begin with AND it was highly counterfeited. I also believe that there were batches that did not make QC from some Sanyo plants that were original Sanyo parts but not first quality that made it back into the distribution chain. This is just my belief, however, and hard to confirm. I think this was the reason that many of what appeared to be original parts had such high failure rates, even from otherwise reliable vendors.

The reason for the 394 series was to replace the 392 series with a more thermally efficient series of parts. They have roughly 10% better thermal properties. Otherwise they are similar, but there may be differences between chips in the muting circuits that create substitution problems.

Bottom line is this: Replace the 392-110 with the 392-150 anytime. I never, use the 392-110. In Hitachis use the 394-160 to replace the 392-110. You may get this to work in other sets as well but it is best not to take chances unless you know there is no other problem other than the ICs. Do not make subs when there may be other variables in play. Generally do not make subs unless you are very certain of the results. Never replace the 392-120 with anything else. Use the 392-180 to replace the 392-110 or 392-150 in Pioneers.

SLR_65 02-23-11 08:06 PM

Re: Steve and Aaron's 51PP9200D-37 Project

Hi Leonard,

The above is confusing me when contrasted with your chip comments in your main convergence repair post at:


There it says:

STK392-120 Hitachi replaces these with STK394-160, for other sets it may not be a good sub.

STK394-160 (This is my choice to replace the STK392-110, -120, & -150 in most Hitachi sets and are available in the kits in the next post)

If Hitachi is replacing the 120 with the 160 then it should at least match the 4 amp rating of the 120 one would think.

I agree though, one probably should stick to the original parts unless one is really sure it's a workable sub and the only subs I've seen for Philips sets with 120s are the sporadic 180 posts and I think those are in error as it sounds to me like the 180 is indeed a 3 amp device. I've seen many posts where the 160s were tried and didn't work and I've not seen even one where they did work, so they are off the table on this set.

It definitely looks like the 120 has no sub save for the 160 in Hitachis when recommended by Hitachi.

I ordered the 120s from Acme just a couple hours ago . . .

Take Care,


lcaillo 02-23-11 09:12 PM

Re: Steve and Aaron's 51PP9200D-37 Project

In the case of Hitachi, they did use the STK392-120 for a short time in some sets when they shifted from the STK392-110. They also supplied the -150 for a quite a while before the 394 series was available. In all Hitachi sets using the 392-110, 392-120, or 392-150, they shifted to the kits using the 394-160. The higher power rating on the -120 allowed it to be used as a sub for the others and you may see some sets that had them. In other sets like the philips products that used the -120, I would stick with that part. The set was designed with the higher current part. The hitachis were designed to use the -110 and direct replacements but sometimes came with -120s.

The bottom line is use what came out of the set unless you know otherwise. That knowledge is not so clear in some cases and may vary between brands, even within brands sometimes.

SLR_65 02-23-11 09:51 PM

Re: Steve and Aaron's 51PP9200D-37 Project

Aaaah, I see. And that answered a question in the back of my mind - I wondered why the 120 wasn't used as an upgrade for the 110.

Good to know, I'll stick your STK recommendation in the repair notebook too . . . that thing's getting thick!

As usual, thanks Leonard!


lcaillo 02-24-11 04:44 PM

Re: Steve and Aaron's 51PP9200D-37 Project

You can use the -120 to replace the -110, but I tend to use them only in Philips sets that they come out of. I try to stick with what the manufacturer intended, or upgrade to the -150 from the -110, other than the Hitachi sets.

SLR_65 03-06-11 09:02 AM

Re: Steve and Aaron's 51PP9200D-37 Project

Hi Guys,

We started on this last night but I was having camera problems so I didn't get many pics took so no step by step guide for this set, at least for now. I'm researching new cameras right now and if I run across another one of these I certainly will do a better write up.

For now a few comments that should help you along . . .

The manual is nice in that it's an electronic document and is searchable, etc. BUT evidently whoever wrote it never took one of these apart!

*) To start a convergence repair grab the manual and read the medium and small signal board removal procedures.

*) Though the manual says you can remove the medium signal board without removing the small signal board we removed it anyway as it's just in your way and it would be hard to see the wiring you need to unhook and to properly label it and stuff.

*) The small signal board removal procedure in 4.1.8 of the manual is a bit flawed. In addition to the screws they show that you need to remove to remove the cover there's also another one hidden. You need to skip down to step 5 and remove the ventillation grid from the side. There's a screw on the right side of that vent hole that also needs removed. (Grrr! This kinda stuff annoys me!) Don't miss the screw illustrated in Figure 4.8 that's on the far lower right - that screw is inside the case a couple inches instead of on the face of the plastic cover like the others.

*) Step 4 of the ssb removal instructions says to "Loosen all connections". Helpful, huh? There are 13 connections that need disconnected. Again, sorry I couldn't document them all for you since the camera was acting up but just label all the wires and the connectors they go to and you'll be fine.

*) Once the small signal board is removed you can start on the medium signal board. Many of the cables you unhooked from the small signal board lead to the medium signal board so you can leave the cables attached to the medium signal board. Make sure to confirm every cable is disconnected before you attempt to remove the board. We had 10 additional wiring bundles to unhook in addition to the 13 we'd already unhooked to remove the ssb for a total of 23 wiring bundles unhooked between the ssb and msb.

*) The medium signal board removal instructions in 4.1.7 are also a bit flawed. There should be a step in between steps 2 & 3 - there's a plastic piece that bridges across the board. I don't know exactly what it does other than provide a place to secure the wiring bundles to, but the feet of that bracket just barely covered part of the circuit board so it needed removed also before the board could be lifted out. It's secured by two screws on each side that screw down into the plastic circuit board support frame. The screws on the outside edge are next to the case so it's a tight fit to get your torx driver (all these are torx head screws) in the screw as the handle hits the case and pushes the bit at an angle instead of straight down. The one on the back side of the mounting foot was especially annoying -> it's not going back in!

*) Step 3 says to remove the fixation screws and shows where they are at - that's accurate, there are four right where they show them, but then it says "Pull the tab on the right hand side of the msb". Sigh, there are TWO tabs that need released to allow the board to be removed. Not a big deal, they are easy to see, but I sure wish someone would proof read these manuals before they are published!

Beyond those discrepancies the rest of the board removal instructions are ok and the pictures are actually pretty good.

*) Once the board is out you should check the twelve 6.8 ohm 1 watt flameproof convergence resistors. For 1 watt resistors they sure look tiny! They are installed in pairs in the circuit with one side to ground so you can test them in circuit, they'll just read 1/2 of their value so they should read 3.4 ohms. The pairs are 3149 & 3150, 3151 & 3152, 3153 & 3154, 3155 & 3156, 3157 & 3158 and 3159 & 3160. The resistors are on the back edge of the board right by the convergence amps, you can't miss them.

In our set 3155 & 3156 were visibly burnt and tested open.

*) De-soldering the chips was a real challenge though! Our Radio Shack desoldering iron just wasn't cutting it! I think they used some lead free solder or something as the solder just wouldn't melt and flow worth a hoot. We had to keep adding new solder, warming it up, then trying to suck it out. It seemed each time you made a little progress, but it took forever. This was the most difficult de-solder job I think I've done in my entire life! After fiddling with one chip for so long I was out of patience so I pulled up on the other chip to stretch the legs a bit and then just cut them with a small pair of diagonal cutters. Then I would put a rubber de-soldering bulb over the cut leg on top and heat the solder pad on the bottom and give it go - that through hole suction coupled with the soldering iron tip being inserted into the hole a bit (the desoldering iron doesn't have a protruding tip) seemed to do the trick, but it was still slow going! Again, I think they were using some new less toxic solder as I've NEVER had as much trouble as these connections were giving us!

That's it for now - when I left last night my son was soldering the new chips in. We're hoping to get it reassembled and test ran tonight unless something pops up (I'm working on picking up a 57" Sony so we may go grab it instead tonight), I'll keep ya posted as things progress and I did get a few pics took so I'll get them up soon too.

Take care,


lcaillo 03-06-11 09:26 AM

Re: Steve and Aaron's 51PP9200D-37 Project

When having trouble desoldering, add some 63/37 solder to the joints and make sure your iron is clean, not oxidized. Clean it often and add more fresh solder to lower the melting point. You can also just cut the chip out and do the pins individually.

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