Hi all! My first post here and a massive headache of a problem as well.
Ok, let’s start from the beginning. I just finished replacing the quick exhaust valve to get the thru coolant spindle working again, which is working great, especially the tool changing! Anyways, a couple of days later I was doing the normal maintenance checks, whilst the machine was turned on. Everything was working fine. Went to go and get some lubrication oil and seen the CRT monitor go fuzzy for a moment and then everything was fine. Filled up the lubrication tank and walk to the front of the machine and the CRT was blank. I first thought it was in a power save mode but that doesn’t kick in after a couple of hours. I turned the machine off and on again, which presented me with a no display and random beeping.
I checked the green light for the CRT monitor was on, which it was. My first thought was the CRT monitor has gone. Power to the CRT monitor is good. I replaced the monitor with an LCD but whilst I was waiting, I thought of hooking up an LCD monitor with an MDA to VGA convertor (which I know works, as I’ve done this before with no problems). Results were black screen & random beeping. So, this led me to think, that the CRT monitor might actually be ok.
After digging through the manual and looking in the cabinet, I can see on the main processor broad the eight led lights, some weren’t lit up.
Run – No light
PGM – No light
CRT - No light
MSG – No light
SIO – Light on
POR – Light on
Halt – Light Dim
+5V – Light on.
The other two board had both +5v LEDs on.
Reading up about it and seeing several forum posts on this site, which I’ll list below, it seems as if I was running into the same kinda problems.
https://www.practicalmachinist.com/vb/haas/haas-vf-3-wont-start-up-297623/
https://www.practicalmachinist.com/...brain-crt-small-e-all-time-input-line-351515/
https://www.practicalmachinist.com/vb/haas/haas-cnc-mill-crt-284207/
So, I decided to dig a bit deeper by checking the voltage on all three boards and on the low PSU (which is the old AT PC PSU). The PSU is fine and the readings on the three boards are:
Controller PCB Voltage
+5V = 4.98V
+12V = 12.23V
-12V = -11.55V
Video/floppy PCB Voltage
+5V = 5.094V
+12V = 12.03V
Main Processor PCB Voltage
+5V = 5.059V
+12V = 12.03V
So, to me, voltage to all three boards look good. Going back to the manual again and searching online and I came across the Haas electrical manual (2006), on page 20 showing the meaning of those eight LED lights. Now I am slightly confused on the boot sequence but I imagine that it boots from bottom upwards? MSG states “If this light does not come on, there is a problem with serial I/O or interrupts. Disconnect anything on the external RS-232 & retest”.
I removed the two external RS-232 (Serial User’s Port & Aux Axis Port), booted up and same result. I noticed a blue RS-232 Ribbon that goes from the main processor PCB to the serial keyboard interface PCB, which I removed and booted up. This time the result changed. The random beeping stop & the eight LED lights all lit up apart from CRT & RUN. However, I was still not getting any display.
I disconnect all the board and check for any visual poor solder joints and blown capacitors, after I clean the boards up. I notice a slight decolourisation around C40 on the main PCB, which I replaced and a poor solder joint on the video/floppy PCB, which was also sorted. At the same time, I checked the Battery voltage on the main PCB, reading 2.7V, also replaced with a new battery. (Yes, I did connect another battery to the Ext. Port, before I changed the battery).
With all the boards back in the machine, booted it up and behold.... the same result, CRT & RUN LED not lit. After a couple of days, busy doing jobs, I came back to it and started pulling out a connector, booting it up to see if I get a different result, which in fact I did. After disconnecting the display cable and leaving out the serial keyboard interface RS-232 blue ribbon disconnected, all eight LED main lights came on! Whilst the machine was on with all eight LED main on, I reconnected the display cable but still got no display.
Now I'm at the point where I don’t know if it’s two separate problems or if it’s a voltage problem on one of the boards or what? Hence why I thought I’ll make this post and hopefully someone can help. I’m a small business and I really can’t afford sending the boards off to someone to repair, where I can do the repair work myself. Hell, I’ve done all the repair work since I brought this machine from the previous owners, but this one has stumped me.
If anyone can help or have any suggestions, I would be much appreciated. If I get any updates, I will update this post, so hopefully anyone else who comes across the same problems as me and read this, I might help them.
Ok, let’s start from the beginning. I just finished replacing the quick exhaust valve to get the thru coolant spindle working again, which is working great, especially the tool changing! Anyways, a couple of days later I was doing the normal maintenance checks, whilst the machine was turned on. Everything was working fine. Went to go and get some lubrication oil and seen the CRT monitor go fuzzy for a moment and then everything was fine. Filled up the lubrication tank and walk to the front of the machine and the CRT was blank. I first thought it was in a power save mode but that doesn’t kick in after a couple of hours. I turned the machine off and on again, which presented me with a no display and random beeping.
I checked the green light for the CRT monitor was on, which it was. My first thought was the CRT monitor has gone. Power to the CRT monitor is good. I replaced the monitor with an LCD but whilst I was waiting, I thought of hooking up an LCD monitor with an MDA to VGA convertor (which I know works, as I’ve done this before with no problems). Results were black screen & random beeping. So, this led me to think, that the CRT monitor might actually be ok.
After digging through the manual and looking in the cabinet, I can see on the main processor broad the eight led lights, some weren’t lit up.
Run – No light
PGM – No light
CRT - No light
MSG – No light
SIO – Light on
POR – Light on
Halt – Light Dim
+5V – Light on.
The other two board had both +5v LEDs on.
Reading up about it and seeing several forum posts on this site, which I’ll list below, it seems as if I was running into the same kinda problems.
https://www.practicalmachinist.com/vb/haas/haas-vf-3-wont-start-up-297623/
https://www.practicalmachinist.com/...brain-crt-small-e-all-time-input-line-351515/
https://www.practicalmachinist.com/vb/haas/haas-cnc-mill-crt-284207/
So, I decided to dig a bit deeper by checking the voltage on all three boards and on the low PSU (which is the old AT PC PSU). The PSU is fine and the readings on the three boards are:
Controller PCB Voltage
+5V = 4.98V
+12V = 12.23V
-12V = -11.55V
Video/floppy PCB Voltage
+5V = 5.094V
+12V = 12.03V
Main Processor PCB Voltage
+5V = 5.059V
+12V = 12.03V
So, to me, voltage to all three boards look good. Going back to the manual again and searching online and I came across the Haas electrical manual (2006), on page 20 showing the meaning of those eight LED lights. Now I am slightly confused on the boot sequence but I imagine that it boots from bottom upwards? MSG states “If this light does not come on, there is a problem with serial I/O or interrupts. Disconnect anything on the external RS-232 & retest”.
I removed the two external RS-232 (Serial User’s Port & Aux Axis Port), booted up and same result. I noticed a blue RS-232 Ribbon that goes from the main processor PCB to the serial keyboard interface PCB, which I removed and booted up. This time the result changed. The random beeping stop & the eight LED lights all lit up apart from CRT & RUN. However, I was still not getting any display.
I disconnect all the board and check for any visual poor solder joints and blown capacitors, after I clean the boards up. I notice a slight decolourisation around C40 on the main PCB, which I replaced and a poor solder joint on the video/floppy PCB, which was also sorted. At the same time, I checked the Battery voltage on the main PCB, reading 2.7V, also replaced with a new battery. (Yes, I did connect another battery to the Ext. Port, before I changed the battery).
With all the boards back in the machine, booted it up and behold.... the same result, CRT & RUN LED not lit. After a couple of days, busy doing jobs, I came back to it and started pulling out a connector, booting it up to see if I get a different result, which in fact I did. After disconnecting the display cable and leaving out the serial keyboard interface RS-232 blue ribbon disconnected, all eight LED main lights came on! Whilst the machine was on with all eight LED main on, I reconnected the display cable but still got no display.
Now I'm at the point where I don’t know if it’s two separate problems or if it’s a voltage problem on one of the boards or what? Hence why I thought I’ll make this post and hopefully someone can help. I’m a small business and I really can’t afford sending the boards off to someone to repair, where I can do the repair work myself. Hell, I’ve done all the repair work since I brought this machine from the previous owners, but this one has stumped me.
If anyone can help or have any suggestions, I would be much appreciated. If I get any updates, I will update this post, so hopefully anyone else who comes across the same problems as me and read this, I might help them.
