Schematic/Service Manual Challenge

[Vipersan]

Got another old chunk of old gear on my bench ..
A 10 inch CRT security monitor ...with no horizontal drive ..
I desperately need a service manual and or schematic ..
the latter being more important..
Signals and timebases are generated in a single chip with a lot of pins
LA7680
So the challenge is to find a schematic really ..
Here is a link showing the user manual front pages to give an idea what it looks like.
Eneo VMC-10/2 Manuals
Can anyone help ...??
Only the user manual found so far ..and about as much use as a chocolate fireguard
ENEO VMC-10/2
rgds
VS

 

[Analoguesat]

The tech specs for that one are dated 2002. Thats ancient!

 

[Vipersan]

The tech specs for that one are dated 2002. Thats ancient!

Old ..not ancient ...and this sort of thing I get for repair on a regular basis from Dave at CCS (the drain inspection company)
Sadly I still can't find a schematic..
So if anyone can help ..I'd appreciate it.

 

[Analoguesat]

That one wasnt very well protected on their website - click the link & you get invited to register to get the content.

Right click the link and you can d/l as normal!

 

[Vipersan]

That one wasnt very well protected on their website - click the link & you get invited to register to get the content.

Right click the link and you can d/l as normal!

???
Perhaps I'm being stoopid here but what link ..what website ?

 

[Analoguesat]

https://www.sourcesecurity.com/technical-details/cctv/transmission-telemetry-and-monitoring/monitors/eneo-vmc-10-2.html

 

[Vipersan]

https://www.sourcesecurity.com/technical-details/cctv/transmission-telemetry-and-monitoring/monitors/eneo-vmc-10-2.html

Thanks AS ..
I've been to the website you linked to ..but cannot see a service manual link on it ..
Only tech spec ...which isn't what I'm after ..
Have you actually seen a schematic on this page ?
rgds

 

[Analoguesat]

No - I was hoping you might see something Ive missed but looks like those tech specs were the only semi useful thing there

Ive been having a good google but theres nothing remotely useful for "ENEO VMC-10/2 service manual" coming up. But might be worth dropping source security an email on Monday maybe?

 

[Channel Hopper]

https://www.electronica-pt.com/esqu...k,9bf2ff80de09d6557e38fecc04658147/no_html,1/

 

[dmaavrigdo]

It was a long time ago but no horizontal out used to mean a big transistor or one of the caps.
I would have been mocked for asking for a schematic before checking the transistors and replacing the capacitor/s.

 

[Vipersan]

https://www.electronica-pt.com/esqu...k,9bf2ff80de09d6557e38fecc04658147/no_html,1/

CH ..
Does that link point to a schematic ?
or simply to a search page ..
?
I suspect I may have to join to get access if so as this is all I get when I click it ??

Download not available try:
Schematics/Esquemas

If there is a schematic there ..and you can access it ..
Could you possibly grab it and post it here ..assuming its a small pdf ?

 

[Vipersan]

It was a long time ago but no horizontal out used to mean a big transistor or one of the caps.
I would have been mocked for asking for a schematic before checking the transistors and replacing the capacitor/s.

No horizontal drive signal to the Line driver Transistor ..so no Horizontal output ..
Definately Not an output issue ...no drive in the early stages of the Timebase..
which is why I need the schematic ..

 

[Vipersan]

At least I managed to find a pdf copy of the LA 7680 with pin outs ..
A start I suppose ..

 

[Channel Hopper]

CH ..
Does that link point to a schematic ?
or simply to a search page ..
?
I suspect I may have to join to get access if so as this is all I get when I click it ??

Download not available try:
Schematics/Esquemas

If there is a schematic there ..and you can access it ..
Could you possibly grab it and post it here ..assuming its a small pdf ?

It was working last night (you broke it). Give me a minute.

 

[Channel Hopper]

It was working last night (you broke it). Give me a minute.

I - think - this was the one.

 

[Vipersan]

I - think - this was the one.

Cheers CH ..
Not exactly the same but may well be close enough ..
certainly uses the same Timebase chips for drive and frame output ..
Cheers buddy..
..just a pity they scanner has cropped off the schematic below the LA7680..

 

[Vipersan]

May well have a winner ..though as yet not attached the CRT ...
But I smell ozone ...so there is EHT about 5 to 10 kv spraying off at the final anode connector ..when powered..
This pcb has been sat in a puddle or wet environment and some of the pins on the LA7680 including H drive supply pin were furred ...indicating heavy corrosion ...
Sure enough when I checked supply to pin 25 on the pcb it is low but present ..
Probing the IC pins with the scope ..
Nothing at pin 25 (topside)...so popped the chip off the pcb ..and this left about 5 pins still in the board which had been eaten through by corrosion at board level ..
there was enough left of the pins on the IC to fit wire legs to replace the broken pins ..
So just re-fitted in after cleaning the pcb under the chip ..et voila ...
EHT .
No idea as yet if there are other related issues ..but the H Timebase is now running ..
So ..progress I think..
Thanx again CH

 

[jeallen01]

May well have a winner ..though as yet not attached the CRT ...
But I smell ozone ...so there is EHT about 5 to 10 kv spraying off at the final anode connector ..when powered..
This pcb has been sat in a puddle or wet environment ..

When you've sorted the timebase, I'd look at that EHT cap as well. Many years ago an ex-girlfriend asked me to look at a portable TV that did not work - turns out that had been in her damp flat for a long time and the EHT cap had perished to become like guyere cheese and the EHT had tracked all down the inside of the TV case! Replaced the cap and cleaned & varnished the case, but it never worked properly again (damaged tripler IIRC).

 

[Vipersan]

When you've sorted the timebase, I'd look at that EHT cap as well. Many years ago an ex-girlfriend asked me to look at a portable TV that did not work - turns out that had been in her damp flat for a long time and the EHT cap had perished to become like guyere cheese and the EHT had tracked all down the inside of the TV case! Replaced the cap and cleaned & varnished the case, but it never worked properly again (damaged tripler IIRC).

Sure will buddy ..
Luckilly I still have one or 2 old used Line flyback transformers ..
Knackered ..but EHT caps are still usefull if transferred over..
I will only do this if the rubber is 'tracking'.
This usually only happens if EHT is generated in a damp environment ...and I suspect this unit was simply shelved without drying after use oudoors...
(drain inspection)

 

[Channel Hopper]

Why not sell them a second hand vga monitor?