hafler dh110

[gene french]

the back of the board has 2 grounds labeled...
one is signal ground...the other

Just saw your regulater VDC post. And those readings are the same further out the board away from the regulators, using the ground rail?

i have 3 grounds labeled on back of board....right signal ground...left signal ground....power ground...you can see power ground goes directly to chassis nut with star washer...
l/r signal grounds also show connected to chassis ground....with continuity check on the fluke...
i was using chassis rail for ground and positive lead on pins 2 and 3 of the two regulators
you should be able to read back writing....

 

[gene french]

wow ....
glad to see you back!!!

thank you!!!

 

[VSAT88]

HA , I ain't left. Can't get rid of my ass that easy.

 

[GeorgeP]

i would be very interest in your mods....i did not recap these....do i need to??
i dont know as much as i wish i did...
please document the changes....dont take for granted that i know anything...
thank you for taking your time to help...

Ok...of course...Ill post the schematic change 4 ya. I WISH I took picures of that relay mod. I did document the switch bypass if you want that also.

 

[gene french]

HA , I ain't left. Can't get rid of my ass that easy.

never wanted to!!!
always enjoyed....

 

[George S.]

4 ground planes labeled on board. Since both channels are affected equally, I'd suspect a issue with the Power Ground plain or Power Rails.
Do continuity checks between all ground rails and main ground. Then voltage checks for the + and - rails, using the associated ground plane.
I assume the on/off switch makes and breaks line. If there's anything that makes and breaks rail, look at it closely.
You'll get this figured out. Probably something simple, but weird that two units are doing it if I understand correctly. Later.

 

[gene french]

and they both worked when i got them....

please explain again...i am not sure what you want me to check...

when i checked rail voltages i used chassis...as i saw power gnd bolted to chassis

 

[George S.]

This has a headphone jack? That could be the issue. Spray DeoxIT in it and work the jack.

 

[gene french]

yes...it does...i did not clean it ... never thought i needed to...i dont have headphones...i will tomorrow...i ohmed all pots...all behave normally and left readings match right readings...
i can see physical traces connecting all grounds to chassis. .except right signal ground ...it does show continuity to chassis ...probably grounded through something....i will require more time to investigate...
here are pics at the back side of front panel...

 

[gene french]

4 ground planes labeled on board. Since both channels are affected equally, I'd suspect a issue with the Power Ground plain or Power Rails.
Do continuity checks between all ground rails and main ground. Then voltage checks for the + and - rails, using the associated ground plane.
I assume the on/off switch makes and breaks line. If there's anything that makes and breaks rail, look at it closely.
You'll get this figured out. Probably something simple, but weird that two units are doing it if I understand correctly. Later.

on/off switch good...i checked rail voltage using chassis ground as i can physically see power ground connect to chassis...

 

[gene french]

got up with renewed vigor....soon to be stripped away....lol
i took georges advice and plugged in a male jack into the headphone jack...
according to the manual...it should disengage the amp section....
it did not...
so i took the preamp out of circuit....wired the fm tuner output direct to one of my wopls...
played exactly the same....seems the preamp is not interacting at all with the system...
strange...

 

[gene french]

which made me think a bit...i know...you can see the smoke way over there....lol
i had been running the tuner off of the switched plug on the back of the preamp...
moved it to unswitched....
now switching off the preamp does nothing...keeps playing as before...
wish i knew...

 

[gene french]

did the same with the second dh 110
exactly the same results...
tough one to try to figure out...

 

[George S.]

You do have the tape monitor switches off?

 

[George S.]

Wonder if it's in tape monitor mode. Can always hook tuner up to tape or any other higher level input jack. Then play with the switches. Just don't plug into the phono section.

 

[George S.]

I run the second tuner on Tape 2. I use Tape 1 In and Out for the PL1000S2. I switch the PL1000S2 in and out of preamp circuit using the Tape 1 monitor switch.

 

[gene french]

well....thats two days of my life i can never get back...

up and running....

please, dont ask...

 

[gene french]

but, the original problem is still a mystery....

both units good to go...

a million thanks for all of the interest and suggestions!!!

i learned a ton....

 

[George S.]

When Marias' son was mixing, perhaps he left a tape monitor circuit engaged.

 

[gene french]

When Marias' son was mixing, perhaps he left a tape monitor circuit engaged.

well...i cant explain the original problem....why it stopped working before i noticed the power light out...
but, this thing has a bunch of inputs and outputs...
one column said output...so...i used it...
went back to check again...in front word output one column over was word recording...i had plugged into a recording output...the correct one was labeled direct output...had 2 of them actually...other added via phones...the 101 just has output...
my fault...might as well own it!!!