 This is a Sony PVM 1353 MDU unit, which is a medical monitor And it is from the mid 90s 1995 and it will not power on So instead of just showing you it won't power on just take my word for it because I'll show you how to troubleshoot this and How to hopefully repair it we could do it all in one quick video? So let's just go ahead and get started first thing I'm gonna do is I'm gonna take the shell off this monitor and I've gone ahead and Removed all the screws so it should just easily slide off We'll be ready to start looking at our power supply and that is this board right here on the Left-hand side of the PVM when you're looking at it from the back Now again, please make sure you familiarize yourself with the safety precautions and things that you need to do when you're working with electricity our Monitor is unplugged and we will not be discharging it because we will not be working on the main frame or anywhere Where the anode cap and electricity is charged? But we will be doing some live electrical tests here shortly So just make sure that you're prepared for that now again This is our board working on it's generally held with two Phillips head screws over here So we've removed those screws ahead of time and now you just slip this board down and we're ready to zoom in closer All right. Here's our main power supply board laid down What we're gonna do is we're going to leave these Connections over here plugged in this is our degausing cable This is our power button and then over here is our main plug where our live Wall electricity AC comes in and it's converted to usable electricity inside the power supply all these cables right here they need to be disconnected and placed out of the way and Those are the areas we're going to be probing to get our power power readings and to check our voltage and make sure that We're getting the right voltage out of the power supply now in order to safely run the test We do want to try to get this out a little bit and give it a little bit of room. I've got a Safe mat here to place it on which is anti static mat We'll place that down there make sure those are plugged in and then now we're ready To install a power plug so what I'm going to do now is I'm plugging in our AC current to the wall and then we can come around to the front kind of and We'll just Press our power button and you may hear a little click There's a tiny click you can hear the power going into the Board but again now it's all live if this power supply is in good shape all these will read the correct voltage, so we need to get our Multimeter and run some checks All right, we've got the multimeter here, and I'm going to turn it to voltage I'm going to turn the range or the mode to DC voltage And get it down to The right range there we go on DC and now I'm going to take the negative end and I'm going to put that on the ground pin now they are labeled So we need to put the left ground pin and the very far pin on the left is our 15 volt power So we're going to go ground And 15 volts and we got 17 volts, so that's pretty much Fine, and then it's another ground right here Then we've got two five volt lines So this first one's five volt B We got five volts there, so that one's actually good And then this is five volt a oh If you could see that on the meter, we've actually got point 0.078 and that should be reading close to five So that's our problem. We're not getting our five voltage a off this. That's it. That's our guaranteed problem So let's Take a quick look at the schematics And we'll have to do some more work to figure out what's causing that five volt what components on the five volt line could be out Let's take a closer look at the power supply. There's two screws holding in the shell on or the shield And all you need to do is lift and pull that a little bit towards you when you're on this side And it'll just slip out And the board can pop out too On these tabs. There's tabs Push all those tabs. It'll lift a little. We should be able to just slide it Towards the backside here once we get all those tabs pushed There we go All right, look at something with me here real quick This is the five volt a pin if I look at it it traces over to this point and jumpers over here it's this inductor and then it hits The 7805 regulator here I see 603. So what I'm going to do is I'm going to pull this out And remove it and then we can test it and see if it's actually shorted or failing And if it is this part, I've got one here in the shop and we'll replace it and hopefully get power five volt power out of it I traced our path and it looks like there's a possibility That it could be either of these 7805s because the current will go from this 7805 and it does connect to one of the legs on this one and This is such a cheap part that we can go ahead and replace both of them and even if One of them is is still good. It's kind of a little bit of preventive maintenance The first thing I like to do is remove that screw that holds our Parts to our heat sinks, and then we're going to flip it over and De-solder I'm going to de-solder both IC 603 and 604 and replace them 604 Slide out there nicely And then let's get 603 Slides right out. I will just get some fresh 7805s And get them ready to install Let's get working on this board Here's just my standard 7805 replacements transistors regulators And we're going to install both of them and I see 604 and 603. I've also got some thermal compound We don't need very much of this at all Please remember that when you're using thermal compound, it's pretty much just to Make sure that the plate on the component Has a good surface area contact with the whole heat sink that way the heat dissipates properly So you don't need to add just a ton of this stuff on there You really just need to add very light amount and make sure that just that it can get all over the plate Um, and that way it'll work most effectively But you don't want to just add a ton like a huge glob you can even Use those two parts a little bit to even some of that out Adding too much will actually Not help any and just kind of a waste. It's kind of expensive But What we'll do is We'll get both of these in here Just slide them down in there to start with and then we're going to screw them back in first and solder the legs in second All right, both those are attached to the heat sinks. Just flip it over and we'll solder in the six legs got my flux And rosin core solder here ready I'm just going to clean off my flux residue Pop this in and see if it tests up We used some alcohol pads and cleaned off our flux residue That's our solder joint when I see 603 604 be clean And if we flip it over and inspect this part, we're good All right, here's our power board. It's been reinserted We've got power going in all I've got to do is turn the power on And then we can run our five volt test and see if we get five volts. I've got the meter here And let's go ahead and do it without any more waiting Activate the power And let's recheck our voltage first our 15 volt 17s reading Let's check the other ground pen 4.9 on 5 V be by va 4.9 perfect. Oh, so Now we're getting our five volts coming out of the a That means that I should be able to simply power the monitor off Then for a final test we will plug in the board connectors And I'm just going to go ahead and we're going to power it on and look at the screen Right away. Let's see. It should work. All right We've got power on here Wow, so there you go you get the all the voltage right and If the rest of the monitor is in good shape it'll work. Let's get a something that looks good and Throw a picture over in this some kind of video game or something Oh, it's hot in the lab today man. Goodness, but this is definitely working good It's been running for a little bit. I've got some super nintendo going into it right now So just let that be kind of a key to you on this power supply That's how you need to troubleshoot it if you're not having power Into your pvm and do what we did here unplug everything Get your power supply out and then probe your board right here After you send a little bit of power back into it to see if you're getting the right Power some of these other things may be wrong if you have a 15 volt power Problem, it's more likely one of these larger ic's that's got you know like seven or eight legs on them and There's also a possibility. It's the capacitors But I've had a lot of discussion with save on pad and he told me that more often than or not It is the five volt regulators and the other regulators and things on the board that fails out and so that's just uh That's an easy fix pretty cheap too and Now we've got a working power supply and a working pvm Thanks again everybody. We'll try to Stave off this summer heat in the shop And I'll definitely see you all next time with some more retro content