Home Theater Forum and Systems banner

1 - 15 of 15 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
hello. after hours of google searching i'm glad to have finally found a site like this! i was about to give up. anyways, i have a rca rt2870-a surround sound receiver and am in need of a service manual or a schematic with parts list or maybe someone on here will know exactly what i need. the unit has power. standby light on front panel stays on. when i press the power button it will turn on then right back off. i opened it up and found a fried resistor, R202, but the color bands are gone and i can't find any info any where. there is also a semi burnt diode, D213, but i can barely see the writing. any help or info would be greatly appreciated. i am a MECP advanced certified mobile electronics installer but i like tinkering with broken electronics as a hobby. i'm assuming these parts are part of outputs and that theres probably a transistor that needs to be checked as well but i'm not very familiar with home theater stuff. i do know my brother didn't understand that it didn't have to be blasted wide open all the time so i know it's been pushed to it's max. we have a better system now but i couldn't resist tearing into this one! thanks for any info and this is an awesome site!! keep up the great work!!
 

·
Plain ole user
Joined
·
11,121 Posts
There are links to web sites that have service manuals, some free, some for a fee, in the Service and Support area stickies. If you can't find a schematic, you may be able to use one channel as a guide if the problem is in a channel with identical components or a mirrored layout.
 

·
Premium Member
Joined
·
8,112 Posts
Hello,
I believe that your RCA is a HTIB. As you can find the whole enchilada for well under $200 in Flea Bay, the juice might not be worth the squeeze as far as fixing it. If you are lucky enough to have a good local Electrical Repair Shop, it is certainly worth having them do a Diagnostic, but I would not sink too much money into it.
Cheers,
JJ
 

·
Registered
Joined
·
246 Posts
I have an RCA 2906 and it is junk. Maybe I should classify it as one step above trash. The RCA manuals I've seen do not include schematics. Sounds like a power supply problem to me.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
thanks for all the replies! yeah i know it's really not worth fixing but as i mentioned tinkering with broken electronics is a hobby of mine and seeing as how there didn't seem to be much wrong with it i just wanted to see if i could get it going again. if not then i'll just use it for parts. it doesn't seem to be a power supply issue cause the standby light stays on and it will power up for a split second then shut off as if it's going into a protection mode, which is my suspicion since the blown components are in the audio output section and not the power supply section. as for using the opposite side of the stereo layout as a guide, they are laid out similar, but resistor values and a couple other small things are a tad bit different. but, like i said, it's really no big deal and it's the challenge to fix it that keeps me interested, not the fact that i really need it fixed. thanks for the replies and once again this is an awesome site with so much very helpful information!! keep up the good work!!
 

·
Registered
Joined
·
9 Posts
the one in my living room is behaving the same way as of today. my wife plugged her ipod into a minijack to RCA adapter cable I had running into the spare RCA inputs on the back rather than into the front mini jack aux input and she says it made a loud pop, but all I know as of right now is it smells like a blown capacitor.

I suppose I'll pull the case off and have a look. what a shame, we only had this thing hooked up for about a month...
 

·
Registered
Joined
·
9 Posts
just pulled the bad board, looks like resistor 202, next to a small cap and a transistor on a small heat sink, I'll try to figure out what value it is, it's toasted, but not completely burned off...

[edit]

out of curiosity, where was diode 213? I looked all over the amber power supply board but couldn't seem to find one with that designation...
is it on another board? because the damage on mine appears to be extremely centralized around r202. the little cap, c211, doesnt even appear to be toast, the etch going from r202 to it is a little yellower, but it doesn't appear to be blown. pretty strange considering I thought it smelled like a toasted cap...

also, for reference, I'm fairly sure the bottom ring of r202 was gold, the in the center is a dark black ring, could have been black or another color that burned to black. above that is a burned up ring, one that seems to have been white to begin with as a small area of it facing the transistor is still white. and the top ring is mottled so it's really hard to make a guess of it's original color...

I'm going to call my father, he has an EE degree, maybe he can help me track it down. if I can fix it I'll post results. I also fix amplifiers and stereo equipment as a hobby so I'd love to be able to share any information I come up with
 

·
Registered
Joined
·
9 Posts
just noticed a little interesting bit of information, the psb from the rt2870 is labled rt2770, another model of system, perhaps this may be of some help.

wish I could track down the manufacturer of the psb so I could see if they still had any schematics laying around. also, my psb was manufactured in march of 2007, if anyone knows of any year to year changes.

just keeping this thread posted with new info as I come across it.
 

·
Registered
Joined
·
9 Posts
found this, but it doesn't seem to jive...
http://www.fixya.com/support/t14175548-need_new_resistor_rca_rt2770_number

I need a new Resistor for my RCA RT2770 the number by the resistor is R202, does anyone know what size the resistor is?
I just need to know what kind of resistor to get if I dont already have on I can see the colors of the rings on it still but I dont know what size it is from top to bottom the lines are a very light brown, then an orange, then a either very very dark brown or a black, and last a medium shade brown
unfortunately this person had no idea how to read a resistor...

More info!

http://www.fixya.com/support/t7790120-rca_rt2780
 

·
Plain ole user
Joined
·
11,121 Posts
There are lots of resistor calculators online, but it is often hard to distinguish the colors on a damaged resistor. One should always try to find a service manual when servicing anything to get the right parts. A good source of manuals is elektrotanya.com.
 

·
Registered
Joined
·
9 Posts
thanks!

I found a great thread from a guy who's SMPS PSB even has the same exact build date as mine, March 23rd 2007...

a guy there even drew a diagram of the switching power supply on a bottom view of the PCB for everyone to check out...

http://www.badcaps.net_RCA2870-r202




[edit] may have found a living soul on earth whose rt2770 smps psb doesnt have r202 burned to smithereens on it. post is from 2011, so it's a stretch, but maybe we can get a reply?

http://www.tomshardware.com/forum/57526-6-help-find-resistor-receiver#bas
 

·
Registered
Joined
·
9 Posts
WEll I determined that the resistor, being just part of a noise cancelling circuit, can be removed and the device will power on. the cause of the burned up resistor though, is a blown IC in the amplifier board of the device...
 

·
Registered
Joined
·
5 Posts
hello. after hours of google searching i'm glad to have finally found a site like this! i was about to give up. anyways, i have a rca rt2870-a surround sound receiver and am in need of a service manual or a schematic with parts list or maybe someone on here will know exactly what i need. the unit has power. standby light on front panel stays on. when i press the power button it will turn on then right back off. i opened it up and found a fried resistor, R202, but the color bands are gone and i can't find any info any where. there is also a semi burnt diode, D213, but i can barely see the writing. any help or info would be greatly appreciated. i am a MECP advanced certified mobile electronics installer but i like tinkering with broken electronics as a hobby. i'm assuming these parts are part of outputs and that theres probably a transistor that needs to be checked as well but i'm not very familiar with home theater stuff. i do know my brother didn't understand that it didn't have to be blasted wide open all the time so i know it's been pushed to it's max. we have a better system now but i couldn't resist tearing into this one! thanks for any info and this is an awesome site!! keep up the great work!!
joeyglvr,

D213 is the same as D204, a fast recovery diode. D213 is filtered by C236, then goes through high frequency filter coil L205 and out to connector CN203, which goes to the processor board. You may have a failing component on that board if D213 is getting hot, so may want to test the load (amperage) going there.

For more info on this power supply, see my thread at:

http://www.hometheatershack.com/forums/diy-repair-maintenance/70387-rca-rt2770-r202-c211-power-supply.html

Cheers!

OMR
 

·
Registered
Joined
·
5 Posts
pics of my resistor:



HCC,

I'm not sure of the color bands I'm seeing here. Is it Brown, white, black, gold? Gold is the tolerance percent rating (5% for Gold) and always must be the 4th band, so what is it.

If it is Brown, white, black, gold then value is 190 ohms, which should be right for this "snubber network".

For more info on this ckt and snubber networks, see my thread at:

http://www.hometheatershack.com/forums/diy-repair-maintenance/70387-rca-rt2770-r202-c211-power-supply.html

Cheers!

OMR
 
1 - 15 of 15 Posts
Top