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richwheat
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monitor problem

Post by richwheat »

Hi, I own a Vektorlogic MEGA ARCADE games console 2004, and the CRT display has a collapse vertical deflection. There is a burnt out resistor that supply's the IC TDA1675A pin 14, I'm trying to get the circuit diagram for the CRT monitor boards and the only information I can find on the main circuit board is JCE-20A and the CRT neck board has JCE-20B. Is anyone able to help identify the manufacture of this CRT monitor so I can identify the burnt out resistor. Regards, Richard
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grantspain
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Re: monitor problem

Post by grantspain »

photo would help
if the resistor to the ic has burnt up then likely the ic is bad
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Re: monitor problem

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Yes the resistor has burnt out and the TDA167A has a short between pin 14 and ground, replacing the IC is not a problem, I'm looking to find out the value if the resistor but need the circuit diagram for this make of chassis. Richard :)
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grantspain
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Re: monitor problem

Post by grantspain »

yes a photo of the chassis would help an awful lot
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Re: monitor problem

Post by NoAffinity »

Based on the reference to the TDA1675A, it might be a hantarex. Not sure how many chassis used that particular component, but I recall it from a Hantarex 9110 that I brought back to life for a friend.

Here's a manual for the Hantarex monitors. Any resemblance?

https://www.arcade-museum.com/manuals-m ... onitor.pdf
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Re: monitor problem

Post by richwheat »

Thanks for reply, but that manual refers to the TDA1670 not the TDA1675A. Also my monitor is about a 20"
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Re: monitor problem

Post by NoAffinity »

richwheat wrote:Thanks for reply, but that manual refers to the TDA1670 not the TDA1675A. Also my monitor is about a 20"
1675A is a replacement for the 1670A, and is likely the component used if it was already replaced.

14", 16" and 20" manual:

https://www.arcade-museum.com/manuals-m ... Manual.pdf
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Re: monitor problem

Post by richwheat »

I've managed to replace the IC TDA1675A and the resistor location is R840 on the chassis board JCA-20A. The resistor is badly burnt and not possible to identify it value by the colour bands, how ever it has a resistance of about 460 ohms but not sure if that's the effect after being burnt (current overload due to IC TDA1675A being short circuit from pin 8 +VCC to pin 14 ground) so finding the correct value of this resistor would be helpful. Do metalfilm resistor change there value if subjected to heat due to current overload?
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Re: monitor problem

Post by richwheat »

Chassis and burnt resistor, can anyone help identify this manufacture.
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grantspain
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Re: monitor problem

Post by grantspain »

looks like intervideo, not sure of model number-might be a VP
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Re: monitor problem

Post by grantspain »

it that resistor is on the vcc pin 14 to the tda 1675 then I would expect it to be something like 2r7 or 4r7 metal oxide
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Re: monitor problem

Post by PrincessPrinPrin »

It's a Semio (aka "Monitor"), model Pico. R840 is 2.7 ohm flame proof type.
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Re: monitor problem

Post by richwheat »

Thanks for the information but can you provide the circuit diagram or tell me where I can get it. Why is each circuit board connected to the chassis identified with JCE-20A/B/C/D. You mention that R840 is 2.7 ohms, could you provide more information as the +Vcc before the resistor is about +26 volts and didn't want to put a 2.7 ohm resistor as this will apply almost +26 volts to the TDA1675A pin 14 and not sure if this will cope. Thanks for the earlier information its really helpful.
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Re: monitor problem

Post by grantspain »

+26 is spot on for this ic, infact pretty sure it run up 30-35v
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Re: monitor problem

Post by NoAffinity »

tda1675a.png
Yup 35V max at pin 14.

datasheet with example circuits here: http://pdf1.alldatasheet.com/datasheet- ... A1675.html
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Re: monitor problem

Post by PrincessPrinPrin »

richwheat wrote:You mention that R840 is 2.7 ohms, could you provide more information as the +Vcc before the resistor is about +26 volts
:lol:
e.jpg
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