So I got a New Astro City - the screen was not working
Screen is a Toshiba Tube (labeled MS9-29 SU) , Chassis is also a MS9-29 SU (with a Nanao 05A00585D1 printing on it)
I decided to start with recapping the chassis - put it back together, screen was working perfectly. Sadly just for a few weeks
Since it's a vertical problem I reflowed the complete neckboard, the vertical deflection IC and the complete vertical IC area => but still the same problem .
So I'm out of ideas & stuck & I need somebody who is smarter than me when it comes to screens ( where are you @grantspain )
Here is the problem:
Picture after start of the cab:
Picture after ca. 30 seconds:
Title screen
In game
Picture after ca. 1-2 minutes:
Picture after ca. 5 minutes (perfect - as it should be from the start ) :
When it is perfect like in the last picture and I turn the cab off to switch out a PCB (1-5 minutes) and turn the cab back on it is perfect again .
When I turn the cab off for longer than 1 hour and turn it back on the problem starts from the beginning .
I need help please .
MS9-29 SU (Nanao Chassis 05A00585D1) problem
- dingsbums
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- RMRM
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Re: MS9-29 SU (Nanao Chassis 05A00585D1) problem
Until Grant the guru arrives to save the day you could check the b+ voltage, i had a chassis that had a very similar effect before the b+ was adjusted.
It never hurts to check.
It never hurts to check.
- grantspain
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Re: MS9-29 SU (Nanao Chassis 05A00585D1) problem
it could be either the LA7837 or the LA7853, if it is vertical roll then it will be the latter
- dingsbums
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Re: MS9-29 SU (Nanao Chassis 05A00585D1) problem
I have never measured the b+ voltage, so please let me know how / where to measure it . And how much voltage it's supposed to have, please.RMRM wrote:Until Grant the guru arrives to save the day you could check the b+ voltage, i had a chassis that had a very similar effect before the b+ was adjusted.
It never hurts to check.
I reflowed the 2 vertical pots on the chassis, the LA7837 & LA7853, the complete areas around the 2 LA chips, the connector to the remote on the chassis, the complete neckboard & the complete remote.
The problem is still the same .
Thanks for pointing me in the right direction, mate . It doesn't roll, it's more like the picture is divided in two parts in the beginning and after ca. 30 seconds it does fold/roll together to one picture .grantspain wrote:it could be either the LA7837 or the LA7853, if it is vertical roll then it will be the latter
With the top part of the picture looking liks it's folded over the top edge and this decreases slowly in about 5 minutes until the picture is perfect.
So you think the LA7837 and/or the LA7853 are bad ? Time to do some ordering .
Just to be sure, are these the correct replacements ?
LA7837
http://www.ebay.de/itm/1-x-LA7837-Verti ... Sw8axaLqml
LA7853
http://www.ebay.de/itm/LA7853-Integrier ... hhoQ15KmNw
- grantspain
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Re: MS9-29 SU (Nanao Chassis 05A00585D1) problem
correct ic, be careful of the tracks -use good quality solder mop
- dingsbums
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Re: MS9-29 SU (Nanao Chassis 05A00585D1) problem
Today arrived the LA7837.
Changed it.
The problem at the top which slowly decreased in about 5 minutes is completly gone .
However the devided picture at startup merging together to one after 30 - 60 seconds is still there => guess that is the LA7853 (which is not here yet ).
Changed it.
The problem at the top which slowly decreased in about 5 minutes is completly gone .
However the devided picture at startup merging together to one after 30 - 60 seconds is still there => guess that is the LA7853 (which is not here yet ).
- dingsbums
- The bead-o empire
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Re: MS9-29 SU (Nanao Chassis 05A00585D1) problem
This week the LA7853 arrived finally.
Soldered it in today => all problems are gone, nice, complete & stable picture at start up of the cab .
Thanks in particular @Grantspain .
Soldered it in today => all problems are gone, nice, complete & stable picture at start up of the cab .
Thanks in particular @Grantspain .