CurtPalme.com Home Theater Forum

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

Just talked to the guy who gave this receiver to my grandson. He said it was in a cabinet in his basement where he had his home theatre setup. It did not get wet, however the surge protector was underwater along with his projector system power plug, which he had connected to HDMI. The projector blew and probably took out the HDMI. He bought it new and it has had no previous problems. I could hook this up, I have all the necessary components, but it would be a major undertaking to get them all together. I would like to have you help me isolate the HDMI problem first.

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

No problem. Just start with testing the list of components I posted.

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

I have to leave for a little bit - I've gone through all IC's and IC95 gives different results, no beeps on 2 tests, I don't know if it's forward or reverse. I'll have to look up the IC. But, it is different.

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

Not sure why your getting beeps. Diode test usually doesn't beep. Only continuity beeps.

IC95 is tied to those 2 diodes I listed for you to test so test them now. Then give me those ic95 readings.

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

D901 and d902 both test good with single beeps (diode test mode) on the forward bias and nothing on reverse as described in the Fluke112 manual. Yet every single IC tested (6 ways) all beeped every test except for IC95 and it beeped on only 4 tests.

.211 beep
.716
.208 beep
.681 beep
.865
.556 beep

I can look this IC up when I get back and give you terminals tested.

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

I looked up your meter and its beep function and for testing these ic's you can just ignore the beep. It's not relevant. What is different between this ic's numbers and another one that you say is different?

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

While your at it and the board is out and not connected to anything, go to BN31 connector on the board and with your DMM on diode scale test between pins 3 and 2 and give me the reading.

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

leg _ IC95 ______ IC91

12__.211 beep__ .212
13__.864 ______ .549
21__.209 beep__ .195
23__.715 ______ .620
31__.681 beep__ .509
32__.553 beep__ .553

For what it's worth all tests on IC91 beeped, I don't know why. But test 13 and 23 on IC95 are the only tests that did not beep. Now that I have some numbers to work from I will test all again and look for significant differences. D901 and D902 tested good and were essentially identical.

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

I'm not seeing anything significant there. Get me that reading on BN31. I'm going to be signing off soon and I was going to right up some stuff in case you wanted to keep working tonight. But would like that reading first.

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

BN31 pin 2 and 3

.448v

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

Going back through IC's comparing voltages.

IC98 12__ .070v this is significantly different, but is enough to make a difference

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

Well now there's an interesting number. Your going to have to lift leg 3, on that ic98, which is the input. Then put the board back in and with everything connected test the DC voltage on the regulator board at ic91 and see if it came up to 4.95v

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

Essentially no change in CN31 pin 2 and 3 @ .5v. I unpugged CN31 and tested the inputs, pin 1 has it's required 15v while pin 3 has only .73v. Should the 5V not be input to the HDMI board?

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

CN31 is back on the video board. Is that where your testing at?

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

YES, I went to the plugin on the video board. Is that wrong?

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

No it wasn't wrong but unplugging that connector is what led us to the HDMI board.With it unplugged your voltage at ic91 was fine and the receiver turned on.

Test for the +5v at pins 4 and 5 on connector CN21 on that video board. Thats where the 5 volts comes in from the regulator board.

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

Retract that, I didn't have a plug BN94 all the way in feeding video. Voltage at CN31 is 4.95v, but goes dead when HDMI is plugged to it. Back where we were. I unsoldered the leg to left on IC98 is that the right one?

jmdigges · Joined: 31 Jan 2012 Posts: 43 Location: tulsa, Ok

My datasheet is blurry, now it looks like it is on the right.

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

If you have your DMM on diode scale and 1 test probe on pin 3 on BN31, and the other probe on any of the legs of that regulator, it will be the leg that shows direct short.

macgyver655 · Joined: 22 Aug 2007 Posts: 6953

Even if you chose the wrong leg, leave it disconnected and also disconnect the other one.