Avalon VT 737 sp

[TheseGoToEleven]

Good morning my friends, yea just tried to desolder them, no luck tho, i ordered a cheap desoldergun for bout 30€ in hope this will do the job https://www.amazon.de/dp/B09GV5B1SR?psc=1&smid=A2ROFELMX9359Y&ref_=chk_typ_imgToDp

This should help a lot compared to using separate heat and suction tools.

 

[punkt]

Sometimes it is tricky to get a good connection with the tip of the probe, so that you can get an accurate measurement. Since your measurements are inconsistent, I suggest taking each measurement more than once, until you are confident about the result. And for resistance you can switch the order of the probes too. Like measure first with the red probe on 2 and black on 3, then with black on 3 and red on 2. Make sure they agree.

Expensive probes have this difficulty too, especially if the surface you are measuring is not pristine. I just hope the measurements are accurate because it’s all we have to make the diagnosis.

What to check next incase k7 turns out to be fine, because i get 0 resistance meassuring right at the legs of the relay

k12 is fine, i measured the wrong pins yesterday

yup k7 seems to be also fine

i suspect something is wrong with k9, because on all the other relays i got readings of 0 while k9 doesnt get any readings on 2&3 and 8&9

while all other relays get a measurment of 180 on 3&4, k9 gets 0

 

[pucho812]

just tested again, nope no readings on 63 or 64 whatsoever even when cranking up gain and output and t12 readin 13, no readings on 63&64

just saw that on the tube card c5 and c4 are flipped upside down, never touched these ones, is this normal?

C5 and c4 are not polarized capacitors so yeah that’s ok as far as orientation

 

[TheseGoToEleven]

i suspect something is wrong with k9, because on all the other relays i got readings of 0 while k9 doesnt get any readings on 2&3 and 8&9

while all other relays get a measurment of 180 on 3&4, k9 gets 0

Pins 3 & 4 on K9 will be shorted (zero resistance) when the relay is "on". So it looks like K9 is stuck in the "on" position even though the unit is unplugged. So K9 should be replaced.

K8 and K9 are supposed to always match. Both on or both off. When the unit is plugged in, they receive the same control signal, which comes from the "EQ->Comp" button.

For an experiment you could try operating the unit with the "EQ->Comp" button turned on, and see what happens. If only K9 is bad, your signal might come back.

 

[punkt]

Pins 3 & 4 on K9 will be shorted (zero resistance) when the relay is "on". So it looks like K9 is stuck in the "on" position even though the unit is unplugged. So K9 should be replaced.

K8 and K9 are supposed to always match. Both on or both off. When the unit is plugged in, they receive the same control signal, which comes from the "EQ->Comp" button.

For an experiment you could try operating the unit with the "EQ->Comp" button turned on, and see what happens. If only K9 is bad, your signal might come back.

what would be the next stage to check after die relays are ok and it still doesnt work?

nope no changes

k7 has 0 ohms between 3&4 is that correct?

as k7 is the relay for the compressor i dont think this is right, seems that it also on the on position, turning on every knob doesnt help really only boosting the eq really does an impact on the test sinewave

 

[TheseGoToEleven]

k7 has 0 ohms between 3&4 is that correct?

as k7 is the relay for the compressor i dont think this is right, seems that it also on the on position, turning on every knob doesnt help really only boosting the eq really does an impact on the test sinewave

With the unit unplugged, pins 3 and 4 should be disconnected from each other (infinite resistance) on all relays. If the resistance is zero then it is stuck in the "on" position and needs to be replaced. Pins 2 and 3 should be shorted together (zero resistance). Also just in case... never measure resistance with the unit turned on.