Newbie: Help finding replacement diode and transistor

[honeydrewboo]

Hello newbie here need some help finding some replacement parts for my Sony Bvm-1910. I found some on ebay but alot of the feedback says that the parts are fake. Rather use mouser/digikey/a reputable company, if possible, could get away with using an smd as well. Thanks!

Hitachi 1SS119 diode and Toshiba 2SA1091 (Q12) Lipple Filter in attached screenshot.

 

[ronsimpson]

Digikey shows 1SS119 but they will come from Rochester Electronics LLC which is somehow connected to Digikey.

2SA109:1 chip cloud I do not know these people.

 

[honeydrewboo]

Thanks for the reply! The only issue with the 1ss119's on digikey is they are in bulk, I do only need a couple of them.

 

[Lightium]

Any of these should be good for the 2SA109: Here

Seems like any diode with a forward voltage 0.8 has moved in type from through-hole to SMD.

You can try NTE, but I've always heard they are expensive. Here

 

[ronsimpson]

For the 1SS119, it looks like the diode is used to temperature compensate the B-E of transistors. In this case only the forward voltage drop is important. The speed of the diode is not but I would stay with a fast diode. The capacitance is not.
1SS119

1N4148, 1N914

I would consider the 1N4148 or 1N914. The forward voltage drop is slightly different, looking at 25C and 1mA.

 

[Nigel Goodwin]

The circuit looks 'similar' to a push pull audio amplifier, and such bias compensation diodes are EXTREMELY critical - and you MUST use the exact original types (or it's likely to self destruct again). For that reason Vbe multipliers are a far better solution.

However, this circuit is only low power, and uses 56 ohm emitter resistors, so thermal runaway isn't going to be an issue - so I would imagine it's not particularly critical at all in this case.

More of a concern is what happened to it? - was it physically damaged?, as it's unlikely to fail.

 

[aliarifat794]

Hello newbie here need some help finding some replacement parts for my Sony Bvm-1910. I found some on ebay but alot of the feedback says that the parts are fake. Rather use mouser/digikey/a reputable company, if possible, could get away with using an smd as well. Thanks!

Hitachi 1SS119 diode and Toshiba 2SA1091 (Q12) Lipple Filter in attached screenshot.

Take the feedback seriously. Buy from a reputed manufacturer/supplier.

 

[honeydrewboo]

The circuit looks 'similar' to a push pull audio amplifier, and such bias compensation diodes are EXTREMELY critical - and you MUST use the exact original types (or it's likely to self destruct again). For that reason Vbe multipliers are a far better solution.

However, this circuit is only low power, and uses 56 ohm emitter resistors, so thermal runaway isn't going to be an issue - so I would imagine it's not particularly critical at all in this case.

More of a concern is what happened to it? - was it physically damaged?, as it's unlikely to fail.

I'm having a power supply issue with the tv I think. I got it up and working for a bit but now I turn it on and it lights the low B led (D10) of the GB protection board. But this board is the BK board and is the video amplifier. I'm a newbie and still learning how to decipher schematics so I appreciate all the help. The transistor tested bad, after I replaced it (found an oem one) the tv fired up. But im having issues now. Something is going on with the +150 and -150 rails. I had a blown resistor on the EB board on the +150 line (R44) and the transistor was bad on the -150 line of the BK Board. Diode tested good after I pulled it, was testing bad in circuit.

Sony BVM 2010 2010 P 2010 PD 2010 PM 2010 PMD 1910 Operation And Maintenance Service Manual : Free Download, Borrow, and Streaming : Internet Archive

Sony BVM 2010 2010P 2010PD 2010PM 2010PMD (should be same model as BVM-1910) Operation and Maintenance Service Manual Broadcast Video Monitor CRT

archive.org

 

[honeydrewboo]

I'm having a power supply issue with the tv I think. I got it up and working for a bit but now I turn it on and it lights the low B led of the GB protection board. But this board is the BK board and is the video amplifier. I'm a newbie and still learning how to decipher schematics so I appreciate all the help. The transistor tested bad, after I replaced it (found an oem one) the tv fired up. But im having issues now. Something is going on with the +150 and -150 rails. I had a blown resistor on the EB board on the +150 line (R44) and the transistor was bad on the -150 line of the BK Board. Diode tested good after I pulled it, was testing bad in circuit.

Sony BVM 2010 2010 P 2010 PD 2010 PM 2010 PMD 1910 Operation And Maintenance Service Manual : Free Download, Borrow, and Streaming : Internet Archive

Sony BVM 2010 2010P 2010PD 2010PM 2010PMD (should be same model as BVM-1910) Operation and Maintenance Service Manual Broadcast Video Monitor CRT

archive.org

Repair Sony BVM 2010P

Recently I've bought a Sony BVM 2010P for retro gaming, unfortunately it has an issue I have not been able to resolve yet. It does not always show a picture. Sometimes when I turn it on it works perfectly, and sometimes it doesn't. When it doesn't, the monitor seems to be powered though, also...

www.electro-tech-online.com

Having similar issues to this thread. It would work fine one day then the next day it trys to start can hear the flyback and it shuts right off and lights the Low B. Tv has all new capacitors as it's from 1988 and most were the blue elnas that tested bad with esr meter. Replaced with all qaulity caps. Flyback was resoldered as well. Nichicon, Rubycon, Panasonic. I have a 1310 I tested the 1910 power supply on and it works so something else is going on

 

[Nigel Goodwin]

A common problem with Sony sets (and all others I suppose) is the CRT, they go low emission and run out of range.

Like most sets from that era and later, they have auto-greyscale - this means they continually adjust the greyscale to keep the picture as correct as possible. However, this adjustment only has a certain range, with the cathode voltage being reduced for any low emission guns - once it's been reduced as far as possible, and it's still not correct, then the sets shut down and display an error code.

You can often temporarily compensate for this by increasing the G2 (Screen) voltage a little, but it's only a short term solution.

It's easy to check - when it's actually working, monitor the three cathode voltages with a multimeter, they should be fairly similar, if one is much lower than the others, then it's likely that gun is low emission.

 

[honeydrewboo]

A common problem with Sony sets (and all others I suppose) is the CRT, they go low emission and run out of range.

Like most sets from that era and later, they have auto-greyscale - this means they continually adjust the greyscale to keep the picture as correct as possible. However, this adjustment only has a certain range, with the cathode voltage being reduced for any low emission guns - once it's been reduced as far as possible, and it's still not correct, then the sets shut down and display an error code.

You can often temporarily compensate for this by increasing the G2 (Screen) voltage a little, but it's only a short term solution.

It's easy to check - when it's actually working, monitor the three cathode voltages with a multimeter, they should be fairly similar, if one is much lower than the others, then it's likely that gun is low emission.

This set doesn't have a potentiometer to adjust the g2 like most consumer sets. This set has an H stat that's connected to the flyback. The knob on the h stat controls convergence and then there is a focus knob. This set was free and sitting behind someone's shed covered up and had been repaired multiple times, bad traces from poor replacement of caps etc. I think you might be on to something, but I think it has to do with the BK board. The guy I got it from said it blew a capacitor off the BK on the red gun rail. I replaced it and cleaned all the old carbon. This does have some trimmer caps on the BK but I haven't touched those.

 

[Nigel Goodwin]

This set doesn't have a potentiometer to adjust the g2 like most consumer sets. This set has an H stat that's connected to the flyback. The knob on the h stat controls convergence and then there is a focus knob.

As is usual on Sony sets the G2 control is on the CRT base, on this set it's RV714 and labelled SCRN, it's directly next to the FOCUS control.

The HSTAT control is something entirely different, and unique to Trinitron CRT's.

 

[honeydrewboo]

As is usual on Sony sets the G2 control is on the CRT base, on this set it's RV714 and labelled SCRN, it's directly next to the FOCUS control.

The HSTAT control is something entirely different, and unique to Trinitron CRT's.

There is not anything next to the focus pot. The C board has no adjustments on it.

 

[Nigel Goodwin]

OK, is that the correct manual?, the one I was looking at was the PVM-1910, screenshot attached.

However, in the screenshot you attached the G2 is connected to connected to C-7, which goes round the top of the circuit to the main board. Doesn't that go to a G2 pot?.

 

[honeydrewboo]

I have a BVM 1910 which is the NTSC version. This is the only service manual I could find but it's for the Pal version of this monitor BVM2010. I checked all the board part numbers listed in that service manual and they are all the same the only difference is the input boards pal vs Ntsc.

 

[Lightium]

I did a search and found this and this. I hope they help.

 

[Nigel Goodwin]

I have a BVM 1910 which is the NTSC version. This is the only service manual I could find but it's for the Pal version of this monitor BVM2010. I checked all the board part numbers listed in that service manual and they are all the same the only difference is the input boards pal vs Ntsc.

G2 control goes to B1 B9, either a pot on another board or (more likely) it's done electronically via a service mode setting. But regardless, just measure the three cathode voltages and see if one is abnormally low.

 

[honeydrewboo]

Alright thanks for the help. Only problem is it only turns on for a split second now then the psu protection board instantly shuts it off. I'll try to take the measurement as it trys to start though.

 

[honeydrewboo]

B9 runs to the BI board ( current control )