Afternoon, would anyone like to take a crack at helpin me figure out whats goin on with this integrated 6500 ii? Picked it up cheap, cleaned it up and out, deoxed the controls but the right channel has loads of static with cd plugged into aux... speaker a and a and b....left channel crystal clear....crystal....but roll the balance control and it goes bad right now.....ive got to believe i should be able test something and get some values...any thoughts, thanks, arc
Pioneer help for noob...
- Thread starter arcspark
- Start date
Hey thanks zeb.....will keep at it for awhile. Will focus on loudness switch too....also looking down on the board it seems like maybe caps leaked or something as there is a dried hardened tan fluid especially on the left by three large caps and on the right by the single large one there...alot of stain on the ones left side....any thoughts appreciated....arc
KingBubba
"Too Much Stuff"
If that amp has High and Low filter switches, they are also a good place to check Try cycling the switches on and off 50 times, turn on the amp and see if that helped. Just for future reference, you only need to check A. A and B are coming from the same point in the amp.
Ok thanks to all, well it doesnt appear to be switch related.....i have deoxed to the point of waste and no real change...flipped switches hundreds of times....so now what baby steps should be done?... ive read a post about maybe bad transistors but i dont know....any thoughts to at least diagnose what to possibly fix....thanks for listening, arc
petehall347
the brandy coffee man
unplug input rca cables . see if still bad . try different input selector position . also try every switch and control . see what is common to all inputs that affects it mostly .
Typical. Balance knob always seems crankier, probably because they sit in one position for years at a time and then when someone finally rotates it, it spreads all that oxidation crap around. I soak it good and stand the box up on the short side and rotate it every hour or so along with working the dial. Sometimes you have to hit it two or three times over the course of a couple days. Remove the bottom cover and squirt it in from there too. Deoxit Gold seems to work better. Sooner or later it'll break lose.
Good advice. I had one where the cap on the input jack was covered with some sort of slimy goo that was preventing contact, cleaned each one with a qtip and contact cleaner and it came to life.
isolate the problem, try CDP into different high-level inputs (Aux, FM), then try CDP into
tape monitors (1,2) which are after the inputs and selectors, etc.
you can then isolate the problem to the preamp/line stage, or the power amp stage.
download the service manual, for the schematic, and if you're game, jumper the
switches (anything on the front) and see if it's a switch problem. do use insulated
probes that clip onto the test points, don't use them manually - one slip and some
thing gets destroyed.
since you have one good channel, you can trace the sound and determine where it
goes bad.
there's so much to do before replacing transistors. could be cold/bad/flakey solder
joints. my static problems were with old/bad caps. (you've identified that with one
good channel it's not the core portion of the power supply). etc.
tape monitors (1,2) which are after the inputs and selectors, etc.
you can then isolate the problem to the preamp/line stage, or the power amp stage.
download the service manual, for the schematic, and if you're game, jumper the
switches (anything on the front) and see if it's a switch problem. do use insulated
probes that clip onto the test points, don't use them manually - one slip and some
thing gets destroyed.
since you have one good channel, you can trace the sound and determine where it
goes bad.
there's so much to do before replacing transistors. could be cold/bad/flakey solder
joints. my static problems were with old/bad caps. (you've identified that with one
good channel it's not the core portion of the power supply). etc.
Ok, its been awhile but here goes .....facts and questions....after cleaning, recleaning every switch multiple times its prob not corrosion, so following what bob, watthour said i tried every input but phono and nothing changes..still bad distorsion, static on right channel. On to something else so when you said jumper switches do you mean to temp bypass to remove them one at a time from the circuit?? If so can you example that for me ?? As the original post stated...NOOB.. i understand the idea of a jumper but want to be sure to do it right...Also... i tested dc bias tonite and right side is 50.6, left is 37.2, fyi....thank you, arc
petehall347
the brandy coffee man
dont forget the mic jack .it has switched contacts and if something was plugged in there recently it may have caused a bad connection .
saying that it should only affect phono .
saying that it should only affect phono .
petehall347
the brandy coffee man
roll the balance control and it goes bad right now.
i missed that earlier ..
i missed that earlier ..
UncleBingo
Super Member
Iirc , that amp has 2sa798 transistors in there. Get them gone asap.
