rodarapan Posted January 28, 2005 Report Posted January 28, 2005 Hello All, Greetings... I have been searching for any datasheet info on this power supply IC (MA6930), and so far after almost six months, I haven't found any. The monitor was manufactured by Mitsubishi but it is sold by Digital Equipment Corp. (DEC). Any help will be much appreciated.Thanks and regards,Rod Quote
hotwaterwizard Posted January 29, 2005 Report Posted January 29, 2005 How about giving all of the Info from the Monitor and we can go from there. Quote
rodarapan Posted January 30, 2005 Author Report Posted January 30, 2005 Hello, Thank you for your reply, appreciate it. Sorry that I did not include any information about the monitor. Here are a few details about it that I have found on the label:Digital Equipment CorporationModel No. VRCX1-W3Chassis Family: W9105FCC ID: BGBTFW9105KPower Supply Board Part No. CT920B3260Another number on the label which might be relevant:CP775C229A20 Also, I would like to find a datasheet of MA2810 which has also failed on this monitor's power supply. The manufacturer's logo on both power supply IC's are Shindengen, but when I went to their website, they don't provide any schematic or pin assigment for the said IC's. I hope somebody in this forum can help me with this...Thanks and regards,Rod Quote
Guest Alun Posted January 30, 2005 Report Posted January 30, 2005 Click Here for a Datasheet for the MA2810 Quote
hotwaterwizard Posted January 31, 2005 Report Posted January 31, 2005 Here is what i found so far.power supply IC MA6930MA6930 CP 267P09202 IC MITSUBISHI MONITOR 57 01MA6930 Power Switching Regulators http://www.pimpworks.org/dec/manuals/http://www.pimpworks.org/dec/http://www.chipweb.de/dsl/index.php?menu=6&level=2&id1=94http://www.ibh-dd.de/alpha/as500.pdf#search='VRCX1W3'http://h18000.www1.hp.com/products/quickspecs/SOC/QB004KMW.DOChttp://h18000.www1.hp.com/products/quickspecs/SOC/QB0051MW.DOChttp://www.ibh-dd.de/alpha/as500.pdf#search='VRCX1W3' Quote
rodarapan Posted January 31, 2005 Author Report Posted January 31, 2005 Hi, Thank you all for the replies... Looks like I am nearing to my quest of finding the correct schematic or information regarding this monitor and the blown parts. When I look at the monitors which was presented to me on my search, I found it that it look similar to Mitsubishi Diamond Pro 91TXM or sometimes refer to as model TFW9105SK. If anybody can point me to the right direction for the schematic, I would be very grateful.Thanks and regards,Rod Quote
rodarapan Posted February 2, 2005 Author Report Posted February 2, 2005 Hello All, After two days of intense searching, I haven't come across any datasheet for MA6930, or schematic of the monitor Diamond Pro 91TXM with model no. TFW9105SKTKW by Mitsubishi. The datasheet for MA2810 that was posted here did not help me much due to no pin assignment information which will give me more idea on how the circuit works. I was wondering why Shindengen does not provide the diagram or at least the pin assignment of the MA2810 pdf they have on their website. The schematic will help me very well if I can get hold of one... Any help will be much appreciated...TIA... Quote
hotwaterwizard Posted February 3, 2005 Report Posted February 3, 2005 Here is a simular Part number but I don't Know if it is a substitute.PT6930.pdf Quote
rodarapan Posted February 3, 2005 Author Report Posted February 3, 2005 Hello... Unfortunately, PT6930 is totally different. The MA6930 IC is directly driving the main transformer that controls the ground connection. The other IC MA2810 controls a smaller transformer to the ground as well. And both of them got shorted out. That's the main reason I want to get hold of the schematic or at least pins assignment of the IC's so I can make changes to the circuit if necessary. We have three of them failed at the same time with the same IC's shorted out. So, I presumed there must be something wrong with the design of the circuit surrounding the IC's, like not enough protection, etc. Also, buying those parts seems tricky as well...Thanks and regards,Rod Quote
fela Posted February 8, 2005 Report Posted February 8, 2005 Hi, rodarapancan you please read the label on lopt transformer?The label on mine is partially unreadable... is like 334P....I think i can help you with your power supply problem!My power supply is working! Quote
rodarapan Posted February 9, 2005 Author Report Posted February 9, 2005 I'll do it when I am in my workshop, right now I am away and cannot access it. Quote
rodarapan Posted February 9, 2005 Author Report Posted February 9, 2005 What's LOPT Transformer? I can't seems to recall the meaning of that. It's been a while since I have heard of that initial. I remember FBT, but can't seems to recall LOPT... Quote
fela Posted February 9, 2005 Report Posted February 9, 2005 Yes, is FBT... (flyback transformer) Quote
rodarapan Posted February 10, 2005 Author Report Posted February 10, 2005 Fela, Hi, I just finish dismantling the input board of the two Mitsubshi's, I have here in the workshop, and both of them does not have a readable part number which was printed on a small paper. The printing has faded and unrecognizable. I even detached one of the sticker and placed it under a microscope to see if I can read it, but that too failed to decern any ligible print. Sorry about that... Quote
fela Posted February 10, 2005 Report Posted February 10, 2005 I'm sorry too...Have you found schematic diagram?Can you post it? Quote
rodarapan Posted February 11, 2005 Author Report Posted February 11, 2005 Hello again, No, I don't have any diagram for this. I am still on the look out for the schematic diagram of this, and also the datasheet with pin assignment of the two IC's MA2810 and MA6930 which will help me modify the circuit to get a better understanding why they are failing. So far, one of them have failed MA2810, MA6930, and two open resistors R918, R922 which are 10 ohms 5 watts. The other one, were all of the above parts plus burnt R905 (130 Ohms) and R906 (56 Ohms). Even the IC's were very hard to locate especially the MA6930...Thanks and regards,Rod Quote
rodarapan Posted February 16, 2005 Author Report Posted February 16, 2005 Just thinking!!! Is it possible that a replacement IC for this discontinued MA6930 be available? Maybe someone have a cross reference book that will give a substitute for this like in a transistor? What I know about it, this IC have a built in MOSFET to drive the main transformer on this monitor's power supply. Will appreciate any thought on this idea. TIA... :) Quote
hotwaterwizard Posted February 20, 2005 Report Posted February 20, 2005 91TXM Monitor MITSUBISHI DIAMOND PRO OWNERS MANUALhttp://www.hightekwiz.com/DPro91TXM_manual.pdf#search='91TXM%20manual' Quote
rodarapan Posted February 20, 2005 Author Report Posted February 20, 2005 Thanks for the User Guide, HotWaterWizard... Appreciate it!!! I am still trying to locate a schematic for 91TXM Diamond Pro, and the part MA6930. The MA2810 is readily available but I cannot use one without the other. Still cannot find a replacement or substitute for MA6930 which I think is discontinued by Shindengen already. I have written to Nec-Mitsubishi.com support and they asked me to ship the item to their repair center for repair but this monitor weigh-in at 78 lbs/35 kilos, which is not too light to ship. Spending money on something I can repair myself is not my idea of fun... The Quest Continues...Thanks and regards,Rod Quote
rodarapan Posted May 7, 2005 Author Report Posted May 7, 2005 Hello Again, Just to give a heads up... Another two of the same monitor failed and still haven't found any schematic for the monitor. I have inquired on some of the online stores I have found but still no luck in finding the parts.Thanks for any help... Quote
rodarapan Posted January 24, 2006 Author Report Posted January 24, 2006 Just a heads up... Still I can't fingd the MA6930 but I found the MA2810 already, but this won't work without the other one... Anybody got some info on this? T I A :DCheers,roar Quote
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