Yamaha RX-V2500 shut down problem

18095 Views 3 Replies 4 Participants Last post by bhachu.simar, Apr 27, 2020

SAGENT

Discussion Starter · Mar 11, 2010

So my RX-V2500 started acting funny a couple months ago. It would just shut off after turning it on. I figured the power cord was coming loose after pulling unit from the cabinet for dusting. I would push the cord back in the socket and the unit would work fine. My brother came accross a RX-V3900 display model for sale at his store and I picked it up for $ 740.00 with 4 year warranty. I pulled the RX-V2500 out and it sat until I decided to sell it locally. Someone came to look at it and low and behold the receiver would turn on for about 5 seconds and click and shut down. This is without anything hooked up to it other than the 120v ac cord. After checking to make sure there were no wire fragments / etc on the binding posts I decided to pull out the circuit board where the 120 V power comes in to check for any obvious damaged components. Visually eveything looked ok. I put the board back in, hooked the wiring back up and now the until will not even turn on, no clicks no nothing. I see you can purchase this board new from yamaha for about $ 150.00 but I don't want to start throwing parts at it as it is not worth as much anymore. Should I try the new board or put it up for sale as parts / repair ? From what I can find on the internet, it seems to be a common problem with many Yamahas but I can not find a sure fix. The receiver has had very little use in the 5 years i've had it and never had any problems until now. It has never been overheated & has been well taken care of. Thanks for your help in advance.

Save

1 - 4 of 4 Posts

lcaillo

· #2 · Mar 11, 2010

Not likely that board. Contrary to what you have heard, this is not a common problem with these units. Troubleshooting any AVR, however, is not trivial and requires the proper mauals and experience, perhaps training. I would not recommend trying to DIY one of these.

There have been some units with a few bad capacitors in the output stage, and some which will shut down because of a ground problem. I would start by tightening all of the screws on the boards and the back panel.

Save

kawal

· #3 · Dec 18, 2013 (Edited)

I know this is an old posting but still comes up on google a lot if you are searching for issues with RX-v2500. I just got one of these defective receivers and wanted to share my findings. First I notice myself and another thread that control side power supply feeding the +/_ 12V DC bus for stabilizers +9V, +5V, 3.3V, 2.5V, -5V runs very hot temperature wise. Secondary hint is from the diagnostic pages of the receiver. Mine was showing PS1:35 and PS2:25 (limit is 24 for PS2 - a summed voltage for power supply B5), What triggered the shutdown each time was PS2. This is also shown in the diagnostic mode. I though that the temperature of the chip might be triggering the shutdown - chip going into temperature protection mode. This is where I found yet another awesome thread with fan modification .
Actually the problem i found in my unit was a temperature / design flaw. i did notice large amounts of heat from the stabilizers therefore I proceeded with the mentioned fan circuit mod. This lowered the temps a lot but still had a shutdown 1/day. I proceeded to remove the stabilizer board that seemed to produce most of heat. You could actually feel the heat coming mostly from the 5V and 3.3V sharp stabilizer chips. When I removed the board i noticed that the stabilizers had a large amount of dried out thermal paste on them specifically on the sharp 3.3V and 5 V stabilizers. These stabilizers were also discolored by the prolonged heat issues and most like were failing. Now I understood that the heat issue was coming from lack of heat transfer between the heatsink and the stabilizers. The only thing holding the stabilizer is a preformed metal bracket that was not doing a good job for the 2 stabilizers in question. I clean the stabilizers, heat sink and applied new thermal compound. I also bent the bracket that pushed the stabilizers to add some extra force on the stabilizers.

Overall I am 99.99% sure that this will fix the issue for me but just in case i have ordered both the 5V and 3.3V replacement parts ( the discoloration suggests a possible failure in the near future). The original Sharp parts are no longer available (PQ05RD21 adn PQ3RD23) but Fairchaild makes a 1:1 replacement (KA278R33C, KA278R05C ) which is available at Mouser.

I also change the stressed out bridge rectifier with a more capable part GBU6G (6A max continuous current vs the original D25BA20 rated at 2A). Just in case a small heat sink was added to the rectifier.

Hope this helps others with this model.