How to access the main speaker relays for cleaning of the contacts. You may also want to clean the headphone(vertical board), center and rear channel relays(top board) while you're at it.
Cleaning the relays contacts, with old amps they were bigger and you could take the middle sector out after removing the spring which created more space for the procedure. My old Sansui AU6900 had problems on one channel... after the procedure the problem was solved...for how long...we'll see. There were black spots on the surface of some contacts and i used a toothpick and a little bit toothpaste to remove them. If it doesn't last i'll buy a new one.
That was my thought with these relays... I could always buy new ones if needed. But almost two years later, this amp is still working perfectly. I use it everyday with my TV
thanks, great video. I have a question, having a problem with my Yamaha hi fi amplifier ax-892. I lost power on speakers. When I turn the amp on, power relay clicks (1st click) , but no click on the speaker relay (no 2nd click). Any suggestions please?
@@johnnycee5179 Yep. No guts, No glory. I just fixed my RX-V995. Shorted elna filter capacitor and drop resistor was open for B- rail to input differentials on main (L R C) amp board. Cap sits close to rectifier heat sink. Replaced 85 deg part with 105 degree Panasonic cap. This fault gives a dc protection shutdown. there's no way to fix it without pulling the amp module out and dangling it around by the wires. But the exact fault was found before any attempt to disassemble by standard trouble shooting methods with just the cover(s) removed, albeit you should know what your are doing in there.
@@johnnycee5179 Thanks. Now it has an intermittent (mostly) when off for a while problem. PS PRT 17%. It's not a hard a fault as the DC PRT. I will find it, but I wish I knew about it when I repaired it the first time. Thought it might go away with use but doesn't look to be. On this model the 17 % means the PRV monitor voltage is 17% of 5 volts (not 3.3 like the newer ones). The acceptable range is 5-15 %. 10% is nominal. Which is what it reads most of the time. i.e 0.5 vdc. It monitors both + and - supplies. I had a realization that I have not seen mentioned anywhere. If a negative supply voltage is low it will result in a high PRV. It is summing + and - supply samples. What is needed here is a multichannel data recorder to figure out what is going on. Update: very intermittent PS PRT was caused by several degraded solder joints on board Video (5) : regulators, a small board which contains 3 voltage regulators and generates a fair amount of heat normally. It is oriented so that it gets similar air flow as the main heat sink. Isolated problem by tapping method. The fault only appeared momentarily and was normal otherwise. The receiver automatically shuts down .5 seconds after it is detected. That makes it sort of difficult to find in this type of unit with 7 monitored supplies which are scattered all over.
