Philips PM3295 and PM3295A

[david69]

Hi, I suppose that "A" version is newer and use inverter for
LCD backlight, older version used graticule? I missed backlight
on my PM3295 and I can`t find any source for LCD into scope
There is inverter 300VAC in service manual, but I miss this
inverter and light plate under LCD. There is anything which should
be shine Thank You for explanation..
David

[david69]

Here are pictures with display and control unit. Supply 13,8V
for display is OK But I don`t have orange backlight
The driver for LCD is PCE2111

[david69]

Can be there LED driver in PCE2111?? as AN for new LCD driver??
Thanks...

[david69]

I was looking into bad capacitors in supply in 5VDC digital
section...

[tautech]

Here I was thinking this was just a CRO and wondering what on earth you were going on about a backlight. 



So yeah, there must be one behind all the LCD panels.

Service manual:
http://elektrotanya.com/philips_pm3295_service_manual.pdf/download.html
30 Mb 322 pages

Wait for "processing" to change to "get manual"

[tautech]

P 47 in the manual has the LCD circuit description along with the supply to it is derived from a +13.8V rail.
It's nominal 4V is ambient temp referenced by transistor V101 to somewhere in the range of 3.5-4.5V.

Is this ^ working as expected?

[david69]

Yes, collector V0101 BCW33 has 4,25V and C101 R113 is
RC for oscillator PCE2111, I have there step down ramps?
I have change BCW33 without efect, no CRO?

[leogala]

I was thinking to replace the lcds of my PM3295A with nice 0.96'' OLED displays available for a ridiculous price on aliexpress. Shouldn't be difficult to interface them with the serial protocol of the led driver, just a bit of reverse engineering on the meaning of the bits.... Anyone interested in the project ?

[leogala]

Done ! Upgraded to OLED with the help of an arduino, less than 20$ in total. So cool ! 

[mvdswaluw]

Done ! Upgraded to OLED with the help of an arduino, less than 20$ in total. So cool ! 

Wow, nice professional look!

[cvanc]

That is absolutely badass.  Well done!

[tautech]

Very nicely done, congrats. 

If you took some time to document the conversion with some pics and code if you want to share it....maybe best in another thread with links to this one.....anyway it could be of great help to others.

[cheeseit]

Very nice!

+1 on documenting this.

[david69]

it is very nice! but You must have different firmware ??
I can`t set Your screen with displayed frequency "kHz" ACvoltage
and etc... So, can I look for newest firmware and change it??

[david69]

my settings, no orange ?backlight?

[leogala]

I reverse engineered the serial protocol by means of an Arduino. Then I implemented the parser on an Arduino mini. If someone is interested I can provide the arduino c source files, I've not documented the protocol but it works perfectly.
This is the link to the displays I used.

[tautech]

I reverse engineered the serial protocol by means of an Arduino. Then I implemented the parser on an Arduino mini. If someone is interested I can provide the arduino c source files, I've not documented the protocol but it works perfectly.
This is the link to the displays I used.

Please do. It helps those that might find this thread in the future and need the same solution/fix.

[leogala]

Ok, I opened a new thread concerning my upgrade.
see: https://www.eevblog.com/forum/projects/pm3295a-oled-upgrade/