Good afternoon,
Wondering if anyone knows the value of the 4 large 2w? or 3w? resistors that reside in locations R601-4? They are reading from 540ohms-630 ohms. All have overheated. Bands barely showing on them. One heated up do much it fell out of the board. One of the 1N4744A zeners are toast too.
Thanks as always
Wondering if anyone knows the value of the 4 large 2w? or 3w? resistors that reside in locations R601-4? They are reading from 540ohms-630 ohms. All have overheated. Bands barely showing on them. One heated up do much it fell out of the board. One of the 1N4744A zeners are toast too.
Thanks as always
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Is it often for resistors to lower in value? I've used both my meter and my MK-328 tester. Resistor readings are right around: 540 (542), 627 (630.1), 625 (627.6), 604 (607.2). The brackets are the MK tester... So, I would have to think the right value could be 620 ohms? Unless they all dropped in value from 680?
What you think Perry? Should I go with 620 or 680? I have to order some no matter what.
All the main output A1275 and C3228 drivers on the board have also heated quite a bit. Although I suppose the zener leaking probably didn't help.
What you think Perry? Should I go with 620 or 680? I have to order some no matter what.
All the main output A1275 and C3228 drivers on the board have also heated quite a bit. Although I suppose the zener leaking probably didn't help.
OK, this amp is driving me crazy. The owner said the amp would work when it wants to. I redid the regulators. They seem fine now, when it ran.
The power supply was just shutting off randomly. After pushing around on things I thought the TL494 was faulty. As when pushed on, the amp would power on and off. I replaced it with a TL494IN, amp seemed fine. Buddy gets it back, says it ran for a minute and shut off. Now won't turn on at all.
After checking the amp over, the VCC+ for the TL494 and the IL4558N is being pulled down. Not sure what is causing it. It's sort of driving me nuts, lol. I removed them both.
The anode of D1 has 13.5v ... but the cathode fluctuates from 5ish volts to sometimes 12+ but usually below 10v.
I've push, probed, twisted... voltage just keeps jumping around. No idea why it's going down.
Any ideas?
The power supply was just shutting off randomly. After pushing around on things I thought the TL494 was faulty. As when pushed on, the amp would power on and off. I replaced it with a TL494IN, amp seemed fine. Buddy gets it back, says it ran for a minute and shut off. Now won't turn on at all.
After checking the amp over, the VCC+ for the TL494 and the IL4558N is being pulled down. Not sure what is causing it. It's sort of driving me nuts, lol. I removed them both.
The anode of D1 has 13.5v ... but the cathode fluctuates from 5ish volts to sometimes 12+ but usually below 10v.
I've push, probed, twisted... voltage just keeps jumping around. No idea why it's going down.
Any ideas?
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Hi Perry... it's similar but def not exact. I have drawn out the circuit. There might be more connections from the top I missed. Pretty much tested every component on the diagram. Not having any luck. Even tried removing the odd component and test to see if voltage came back up and no luck.
I have rem voltage right up to D1. After that, voltage is all from 5-6ish volts. Sometimes will go over 10+ but not often. Just keeps fluctuating.
I have rem voltage right up to D1. After that, voltage is all from 5-6ish volts. Sometimes will go over 10+ but not often. Just keeps fluctuating.
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